So you have an annual budget of around £4k, but only as the money comes in?
The Tiger Club option is a good one, but I'd also go and meet your local LAA strut - they will have a monopoly on cheap and interesting group A aeroplanes.
You will, regardless, almost certainly need to either get out of your current "club spamcan" comfort zone (this is nothing personal, most new pilots have that), and either fly something old and tatty (such as an elderly C150) or unusual.
I'd strongly encourage the latter - you'll learn much more, and once you've got the hang of it, have a lot more fun.
If you are aiming for an airline job (in which case personally I think you should get out more, but that's just me - I'd much rather do just about any other professional flying job but that myself, and at your age look at the services), then you need to stick with Group A (us oldies preferred term for SEP that isn't a microlight), if you just want to get good at flying and enjoy it, then I'd strongly recommend looking at Microlights. There are several good clubs in Kent, and you could do a lot of flying for £4k per year, and most likely also manage to buy either an aeroplane outright, or a share.
Just for example (I don't know the seller, just found the advert randomly).
G